The sale only applies select dates throughout April and May, but flights can only be booked through today, 3/17, at 11:59pm. You'll have to move quick to get your 69 on.
And another super unsexy caveat: you have to join the carrier’s $9 Fare Club, to take advantage of the sale, an additional $59.95. So it's more like $128.99, which looks more like something you'd hear about involving the emperor Caligula than a sale price.
Additionally, because Spirit is Spirit, you still have to pay for baggage, advance seat assignment, and a bunch of other nonsensical fees.
If you’re still into the "deal," head here for the full list of flight routes, and book your spring vacation quick-fast.